It seems that you can never outgrow being questioned by your parents about your fashion choices, even years after you've moved out. We have all heard our parents proclaim that "back in the day," most people didn't go out without at least a button-up shirt, sometimes a tie, if not a coat as well. A t-shirt was long considered underwear; and wandering around town in just a t-shirt was the modern equivalent of wandering around a public place in just a pair of boxers.

He wasn't really far off the mark. Americans were first introduced to t-shirts while they were fighting in Europe during the two World Wars. Military men preferred the cotton crew-neck t-shirts to the woolen undergarments that were standard-issue at the time.

Soon after that however, t-shirts became a symbol of rebellion.

Marlon Brando wore one to show off his physique in "A Streetcar Named Desire." James Dean wore one to show off his indifference in "Rebel Without a Cause." T-shirt sales skyrocketed after those movies. A few years later, countless hippies and activists became rebels WITH causes and used t-shirts to display slogans and political interests.

At the same time, formal wear was evolving as well. Many corporations relaxed their dress codes during the energy crisis in the 70's; they couldn't blast their air-conditioners so their employees were suffering in shirts, ties and coats. The dress code was relaxed a little (button-up shirt and slacks) so that the employees could be more productive.

During the 80's and 90's, an interesting shift occurred. T-shirts were still casual and dress shirts were, for the most part, formal, but more and more t-shirts served as marketing for formal wear. Calvin Klein and Armani Exchange are the more famous examples, but they were soon joined by Gap and Abercrombie & Fitch, among many others. A person wearing a CK t-shirt seemed to say, "I'm dressed casually in this inexpensive t-shirt now, but I can afford its more expensive counterpart." I always thought of it as like driving a Honda with a bumper sticker that said, "My other car is a BMW."

A few years ago, t-shirts made the jump into more formal settings.

They began to appear more and more at clubs, restaurants and other places you would consider "going out." Beginning with plain ribbed t-shirts and v-necks during the late 90's to now, higher-end designer t-shirts emblazoned with "Obey," "Affliction," and "Ed Hardy" are a not uncommon sight.

Over the years, the T-shirt has evolved from a symbol of rebellion into an acceptable article of clothing for even some of the most formal settings. Where you would once get looked down on for wearing a T-shirt in public, it is now much more common to see T-shirts being worn than formal wear.